Electronic cooling water pump with floating impeller

ABSTRACT

An electronic cooling water pump with a floating impeller for a motor vehicle. The mechanism includes a support or housing, a stator, a water pump cover, a socket injection molding, a controller (or circuit board), and a rear cover. A rotor impeller injection molding is positioned at the center of the stator and floats when the water pump is operating. The magnetic field generated by the stator and the magnetic field generated by the permanent magnets in the rotor impeller injection molding turn the motor impeller injection molding at a certain rotation speed, so that the impeller does work on coolant, and also make the rotor impeller injection molding float automatically in the center of the stator. Bearings are eliminated and friction losses and pump noise are minimized.

TECHNICAL FIELD

The present invention relates to a motor vehicle cooling system accessory, in particular to an electronic cooling water pump for a motor vehicle.

BACKGROUND

As society has developed and technology has advanced, motor vehicles have become part of most households, and people are demanding greater comfort when traveling. As a result, the leaders in the field of motor vehicle cooling systems have made constant innovations in cooling system technology to meet these demands.

Abnormal noises in motor vehicles are a common concern and affect the comfort of travelers. Abnormal noise from the motor vehicle cooling water pump accounts for a significant proportion of such noises from motor vehicles, and is also the principal form of failure of coolant pumps. Noise produced by the bearings in coolant pumps is the most significant contribution to the abnormal noise. Thus, solving the problem of the abnormal noise from the bearings of the coolant pump is of importance to the improvement of comfort for motor vehicle occupants.

The motive power for conventional mechanical cooling water pumps for motor vehicles comes from the main shaft of the engine. The motive power provided by the main shaft is transmitted to the motor vehicle's coolant pump shaft via a belt or chain, enabling the coolant pump impeller to do work on the coolant so that the coolant circulates in the cooling system and thereby cools the relevant components of the motor vehicle. The characteristics of transmission by belt or chain are such that the belt or chain must exert a significant radial force on the coolant pump shaft during transmission. For this reason it is necessary to use bearings in a mechanical coolant pump to bear the radial force exerted on the coolant pump by the belt or chain. With bearings, there will be friction, and with friction, there is the possibility of abnormal noise.

The development in recent years of electronic coolant pumps for motor vehicles has provided a fine platform for solving the problem of abnormal noise from the coolant pump bearings. The main difference between mechanical cooling water pumps and electronic cooling water pumps is that their motive power comes from different sources. The motive power for mechanical cooling water pumps comes from the main shaft of the engine, whereas the motive power for electronic cooling water pumps comes from a generator or battery pack. Electronic cooling water pumps do not need a belt or chain for transmission of motive power. It is only necessary to connect the wiring port of the electronic cooling water pump of the motor vehicle to the wiring port of the motor vehicle's power supply.

It is an object of the present invention to provide a cooling pump for a motor vehicle that minimizes or eliminate undesirable noise from the pump. It is another object of the present invention to provide a coolant pump for a motor vehicle without bearings.

SUMMARY OF THE INVENTION

The present invention solves the objects by providing a coolant pump with a floating impeller. The invention includes a support, on which are mounted a stator, a water pump cover, a socket injection molding, a controller and a rear cover. A rotor impeller injection molding is mounted at the center of the rotor.

The rotor impeller injection molding includes a coolant pump impeller and an electric motor rotor. The rotor comprises a plurality of permanent magnets with four being preferred, as well as a permanent magnet support and a permanent magnet protective cover. The pump impeller includes a plurality of blades, a front cover plate and a rear cover plate.

An injection molding process is used to form the pump impeller and electric motor rotor as a single piece. In the injection molding process, the rotor is inserted into the mold and the plastic material is injected into the mold to form a component in which the pump impeller is integrated with the rotor. A through-hole is provided at the center of the rotor impeller injection molding, to fit an electric motor shaft.

When the electronic cooling water pump for the motor vehicle is not energized and is just starting up, the fit between the electric machine shaft and the rotor impeller injection molding ensures that the shaft core of the rotor impeller injection molding coincides with the shaft core of the stator, i.e. at this time, in terms of radial position, the rotor impeller injection molding is located at the center of the stator. The magnetic effect of the permanent magnets in the rotor impeller injection molding ensures that the permanent magnets are located in a central position in the longitudinal direction of the stator. That is to say, at this time, the longitudinal position of the rotor impeller injection molding is in a floating state.

Once the electronic coolant pump has been energized, the stator will generate a magnetic field. The interaction between the magnetic field generated by the stator and the magnetic field generated by the permanent magnets in the rotor impeller injection molding can not only turn the rotor impeller injection molding at a certain rotation speed, so that the impeller does work on the coolant, but also makes the rotor impeller injection molding float automatically in the center of the stator. That is to say, as it rotates and does work, the impeller remains at all times in a magnetic floating state, and so will not experience friction with other components.

Compared with the prior art, the present invention has the following advantages: the cooling water pump with a floating impeller for a motor vehicle dispenses with a bearing, eliminating friction between a rotating part and a fixed part. Thus, it not only resolves the fault of abnormal vehicle noise produced by bearing friction, but it also eliminates consumption of mechanical energy by bearing friction, thereby reducing the fuel consumption of the motor vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional diagram of an embodiment of the present invention.

FIG. 2 is an exploded view of the components of the embodiment of the invention as depicted in FIG. 1.

FIG. 3 is a cross-sectional diagram of an embodiment of the rotor impeller injection molding component in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is described in further detail below with reference to the accompanying drawings.

FIGS. 1-3 depict a preferred embodiment 20 of the invention. The embodiment includes a cooling water pump with a floating impeller for a motor vehicle comprising a support or housing 6, a stator 5 mounted on or in the support or housing 6, a water pump cover 2, a socket injection molding 7, a controller (circuit board) 8 and a rear cover 9. The stator 5, water pump cover 2, socket injection molding 7, controller 8 and rear cover 9 are all fixed to the support or housing by fasteners, such as bolts.

Sealing rings for sealing are mounted between the stator 5 and water pump cover 2, between the stator 5 and support 6, between the socket injection molding 7 and support 6, and between the rear cover 9 and support 6, to prevent leakage. This ensures that coolant will not leak to the outside, and also that liquid and damp gases from the outside will not enter the interior of the motor vehicle's electronic cooling water pump and damage its components.

A fixation process, such as welding, is employed to ensure electric current and signal communication between the stator 5 and controller 8 and between the controller 8 and socket injection molding 7. The controller 8 is preferably a circuit board. When the plug-in injection molding 7 is in communication with a power supply of the motor vehicle and a signal source, and has received a signal, the plug-in injection molding 7 will input the signal and a current to the controller 8. After intelligent processing by the controller 8, the controller 8 will drive the rotor impeller injection molding 3 to rotate at a certain speed; as it rotates, the impeller part of the rotor impeller injection molding 3 does work on the coolant, so that the latter circulates in the cooling system circuit of the motor vehicle, thereby cooling the relevant components of the motor vehicle.

The rotor impeller injection molding 3, which is best shown in FIG. 3, comprises an impeller 12, a permanent magnet support or housing 14, a plurality of permanent magnets 16 and a permanent magnet protective cover 18. In this embodiment, preferably four permanent magnets equally spaced around the support housing are provided. At the instant in time when the electronic cooling water pump for the motor vehicle is not energized and is just starting up, the precise fit between the electric machine shaft 4 and the rotor impeller injection molding 3 ensures that the shaft core of the rotor impeller injection molding 3 coincides with the shaft core of the stator. This means that, in terms of radial position, the rotor impeller injection molding 3 is located at the center of the stator 5. The magnetic effect of the permanent magnets 16 in the rotor impeller injection molding 3 ensures that the permanent magnets are also located in a central position in the longitudinal direction of the stator 5. The longitudinal axis is represented by the line A in FIGS. 1 and 3. Thus, at this time, the longitudinal position of the rotor impeller injection molding 3 in the support housing 6 is in a floating state.

Once the electronic cooling water pump for the motor vehicle has been energized, the stator 5 will generate a magnetic field. The interaction between the magnetic field generated by the stator 5 and the magnetic field generated by the permanent magnets 16 in the rotor impeller injection molding 3 can not only turn the rotor impeller injection molding 3 at a certain rotation speed, so that the impeller does work on the coolant, but also makes the rotor impeller injection molding 3 float automatically in the center of the stator 5. That is to say, as it rotates and does work, the impeller part of the rotor impeller injection molding 3 remains at all times in a magnetic floating state, and so will not experience friction with other components.

The objective ultimately achieved by the present invention is to increase the overall efficiency of the motor vehicle cooling water pump while minimizing or eliminating abnormal noise produced by any bearings.

The present invention can eliminate or substantially diminish abnormal noise produced by a bearing of an electronic cooling water pump for a motor vehicle. This reduces the probability of abnormal motor vehicle noise emitting from the water pump, and hence can increase customer satisfaction.

Not only can the present invention minimize or eliminate abnormal noise produced by a bearing of an electronic cooling water pump for a motor vehicle, but the failure rate after sale of the motor vehicle cooling water pump can be reduced significantly.

In addition, bearing lifespan is one of the main factors limiting the overall lifespan of a motor vehicle cooling water pump. For this reason, a structural design without a bearing, as employed in the present invention, can increase lifespan significantly compared to product designs in the same class employing a bearing members. It is estimated that the increase in lifespan can be 30% or more.

The use of a structural design without any bearings as provided by the present invention, also eliminates mechanical loss arising from bearing friction. This can also increase motor vehicle cooling water pump efficiency, thereby reducing the fuel consumption of the motor vehicle. Eliminating the bearing(s) also can reduce design costs.

In operation, at the instant in time when the electronic cooling water pump for the motor vehicle is not energized and is just starting up, the precise fit between the electric machine shaft 4 and the rotor impeller injection molding 3 ensures that the shaft core of the rotor impeller injection molding 3 coincides with the shaft core of the stator. At this time, in terms of radial position, the rotor impeller injection molding 3 is located at the center of the stator 5. The magnetic effect of the permanent magnets 16 in the rotor impeller injection molding 3 ensures that the permanent magnets are also located in a central position in the longitudinal direction of the stator 5. That is to say, at this time, the longitudinal position of the rotor impeller injection molding 3 is in a floating state.

Once the electronic cooling water pump for the motor vehicle has been energized, the stator 5 will generate a magnetic field. The interaction between the magnetic field generated by the stator 5 and the magnetic field generated by the permanent magnets 16 in the rotor impeller injection molding 3 can not only turn the rotor impeller injection molding 3 at a certain rotation speed, so that the impeller does work on the coolant, but also make the rotor impeller injection molding 3 float automatically in the center of the stator 5. That is to say, as it rotates and does work, the impeller part of the rotor impeller injection molding 3 remains at all times in a magnetic floating state, and so will not experience friction with other components.

Although the invention has been described with respect to preferred embodiments, it is to be also understood that it is not to be so limited since changes and modifications can be made therein which are within the full scope of this invention as detailed by the following claims. 

What is claimed is:
 1. A floating impeller structure for a motor vehicle cooling water pump, comprising a stator member , an electric machine shaft member, a rotor impeller injection molding, and a plurality of permanent magnets wherein said rotor impeller molding has an open central core for positioning of said shaft member; and wherein the magnetic effect of the permanent magnets in said motor impeller injection molding positions said permanent magnets centrally in the member.
 2. The floating impeller structure for a motor vehicle cooling water pump as claimed in claim 1, wherein said rotor impeller injection molding comprises a water pump impeller and an electric machine rotor, said electric machine rotor comprising said plurality of permanent magnets, a permanent magnet support, and a permanent magnet protective cover.
 3. The floating impeller structure for a motor vehicle cooling water pump as claimed in claim 2 wherein said permanent support is positioned centrally both radially and longitudinally in said stator member.
 4. The floating impeller structure for a motor vehicle cooling water pump as claimed in claim 2 wherein said water pump impeller comprises a plurality of blade members.
 5. The floating impeller structure for a motor vehicle cooling water pump as claimed in claim 1 wherein said water pump impeller and electric machine rotor comprise a single member.
 6. The floating impeller structure for a motor vehicle cooling water pump as claimed in claim 5 wherein said rotor is injection insert molded into said impeller injection molding.
 7. The floating impeller structure for a motor vehicle cooling pump as claimed in claim 1, wherein said electric machine shaft member is fixed at the center of the stator, wherein said shaft core coincides with that of said rotor. 